Generally, manufacture of a snack food involves some form of extrusion of cereal/pulse dough followed by frying. Some times such products are also roasted for direct consumption, such as papad, or wafers. It is a common practice to add fat (shortening) to obtain the product crisp. In many developed countries they are usually prepared by high-pressure extrusion to achieve high degree of expansion. In India these are made by forming extrusion (or sheeting by rollers) optionally with addition of some leavening agents followed by deep-frying in oil or roasting, leading to a crisp product.
A few processes available for the production of low-fat products in different countries are described.
Reference May be made to Lanner et al., 2000, the Procter & Gamble, Cincinnati, U.S. Pat. No. 6,033,707 wherein a fried snack product is extruded and shaped into a design. The dough is formed by mixture of starch-based flour with a specific ratio of gelatinized starch and an amount of protein. The emulsifier keeps the integrity of the structure of the product. However, this product is deep-flied and may not result as a low-fat product.
Reference may be made to Reed et al., 1999, The Procter & Gamble, Cincinnati, U.S. Pat. No. 5,922,386, wherein a reduced fat, shaped snack product having light, crispy and crunchy texture is prepared. The product has the fat content of 20-38%. However, this product is starch flour based and the fat content in the product is much higher than in the present investigation.
Reference may be made to Lodge et al., 1995, The Procter & Gamble, Cincinnati, U.S. Pat. No. 5,464,643, wherein a low-fat, shaped fried snack product having light, crispy and crunchy texture is prepared. The product is starch flour based with 3% hydrolyzed starch. The dough is formed and made into sheets and fried to provide a snack having 20-32% fat and having more flavors. However, the fat content in the product is much higher than in the present investigation and the product is not soy based.
Reference may be made to Villagran et al. 1994, The Procter & Gamble, Cincinnati, U.S. Pat. No. 5,362,511, wherein a fried snack food based on cereal grain having improved qualities are developed. The cereal grain based dough containing a protein is extruded and deep-fried to have reduced gumminess or tooth packing and grittiness. However, this product is deep-fried and may not result as low-fat product.
Reference may be made to Maegli-JW, 1994, Beatreme Foods, Beloit, Wis., USA, U.S. Pat. No. 5,298,268, wherein, a low-fat, seasoned, cereal-based snack food having low moisture content by the use of an adhesive is described. However, this is not a soy-based snack.
Reference may be made to Finger-P J and Eckhardt-D, 1994, Kernel Foods, London, NW-10 6EX, UK, UK patent No. GB 2270613A, wherein the method of making a snack food involves the preparation of dough from durum wheat flour and water, shaped, fried and cooled rapidly. The snack mentioned here is wheat based and not soy.
Reference may be made to Lodge R W and Allen C H 1993, The Procter & Gamble, Cincinnati, U.S. Pat. No. 5,188,859, describing the process for preparing a low-fat snack with a light, crispy, crunchy texture, made from potato flour, sheeted, cut and coated with oil and cooked with hot air or superheated steam. The cooked snack contains 10-20% fat, having fried like texture and flavor. This product is prepared with potato flour and not soy.
The reference may be made to Young et al., 1992, The Procter & Gamble, Cincinnati, U.S. Pat. No. 5,171,600, wherein a process for preparing a low-fat shaped snack product having a light, crispy texture prepared from 50-80% potato flour, sheeted and cut or extruded, fried to moisture of 5-15% and excess fat removed by superheated steam, resulting in a snack having 12-25% fat is described. However, this product is not soy based.
Reference may be made to Ueda et al., 1991, Otsuka pharmaceutical co. Lmt. Tokyo, Japan, U.S. Pat. No. 505,270, wherein, a high protein nutritive food which has a protein content of 40-85% (based on solids) is prepared by heating the dough under reduced pressure using soy proteins. However, the formulation and method of preparation is different from the present product.
Reference may be made to Gage et al 1988, The Procter & Gamble, Cincinnati, European patent No. EP 0287158A2, describing the preparation of extruded-cooked snack chips comprising corn, fat and water. The chips are lower in fat and higher in fibre than conventional snack chips containing up to 1% emulsifier, having light texture, an absorbent material for crunchiness. Process involves extrusion cooking to 60-80% gelatinization and fried in shortening. However, this product is prepared by extrusion cooking and is corn based.
Reference may be made to Willard M J, 1988, Willard, Idaho Falls, Id., USA, U.S. Pat. No. 4,770,891 wherein, an expanded fried cereal-based snack product are prepared from a low-water-absorbing component, a high-water-absorbing component and a starch component. The total dry solids are mixed with water to form dough, sheeted, cut into pieces and fried in hot oil to form a fried snack with low-fat content. This is totally a cereal-based snack product.
Reference may be made to Willard M J, 1988, Willard, Idaho Falls, Id., USA, U.S. Pat. No. 4,769,253, for the preparation of an expanded fried cereal-based snack product is given comprising low-water-absorbing component, a high-water-absorbing component and a starch component, extruded and fried in hot oil, to get a low-fat snack. The snack that mentioned here is cereal based.
Reference may be made to Open Shaw and Toft 1987, D&S Bolton UK, UK patent No. 2178637A, wherein, water is added to a mixture of wheat bran and ungelatinised starch and cooked to give a plastic mass, which is sheeted and cut. The cut pieces are fried in hot oil. The protein can be enhanced with caseinates, soy protein or wheat or corn gluten. The finished product has a high fibre content and fat more than or equal to 5%. The finished product is rich in fibre and starch based and soy is incorporated to increase the protein content.
Reference may be made to Willard M J, 1986, Willard, Idaho Falls, Id., USA, U.S. Pat. No. 4,623,548, wherein, dough is prepared from low-water-absorbing component, a high-water-absorbing component and a starch component, mixed with water to form dough, extruded and fried to form a snack of low-fat content. However, the product mentioned here does not contain soy.
Reference may be made to Wiker and Cunningham, 1983, Kansas State University Research Foundation, Manhattan, Kans., U.S. Pat. No. 4,421,770, wherein, a high protein snack food prepared from egg protein by involving a process of heat coagulation. The principal ingredient is starch in the batter mix. However, the product is not soy based and not a low-fat product.
Reference may be made to Howard A N, 1982, South African patent No. ZA 81/7470, describing the method of preparation of crisps having low calorific value even when fried. They consist of discrete cooked portions of dough of gelatinized starch and cereal bran other than rice bran as a tiber. Oil content is preferentially 5-30%. These are mainly starch-based crisps and do not contain soy.
Reference may be made to Toft J G, 1980, Standard Brands Inco. U.S. Pat. No. 4,212,892, wherein, a high protein extruded snack food comprising a plastic protein gel with dry potato/corn starch or flour is developed. The protein gel is prepared using fish and soybean. The snack food is nutritionally superior to potato chips, having protein level of 18-20%. However, this product is deep-fried and may not result as a low-fat product and the source of protein is from animal and plant sources. The product is prepared using pre gelled soy protein.
Reference may be made to Rockland L B and Radke T M, 1978, United States of America, Secretary of Agriculture U.S. Pat. No. 4,124,727, describing a process for preparing a legume based, nutritionally balanced protein food product. The process includes treating the seeds to render them quick cooking, cooking the seeds and mashing and mixing with methionine containing cereal flours, oil seeds etc., adding water to form a dough, extruded and fried in oil.
Reference may be made to Hahn D T, 1978, Ralston Purina Co. St. Louis Mo., U.S. Pat. No. 4,120,988, wherein a protein based snack food having expanded and puffed texture using soy protein isolate are developed. Soy protein isolate is in the form of gel, which maintains the structural integrity of the product. However, the formulation is based on processed soy proteins.
Reference may be made to Huelskamp et al. 1975,U.S. Pat. No. 3,911,142, wherein, a process for preparing a protein snack food is described, consisting of soy protein, dried whey and dried skim milk, wheat flour, potato flakes, flavor etc., adding some of the water and dry mixing the ingredients and resting the mass and adding the remaining water, forming sheets of dough and cutting into shapes and baking the product followed by air dehydration. The dough pieces may be fried also.
Reference may be made to Blagdon et al., 1974, Ralston Purina Co. St. Louis, Mo., U.S. Pat. No. 3,849,582, wherein, an aqueous mixture of a pre-gelatinized starch, soy protein isolate which has not been subjected to the gelling action of heat and a starch modifying and complex forming agent is shaped and fried to give a product with an improved crisp texture. However, this product is deep-fried and may not result in a low-fat product.
Reference may be made to Nestle S A. 1974, British patent No. 1350547, for a product, containing dough compositions of 14-16% protein, are extruded, frozen, sliced and deep-fried. The product under consideration is a fried product, which will not be a low-fat product.
Reference may be made to Sato et al 1973 Japanese patent No. 3843622, describes a process consisting of a mixture of soybean and vegetable materials. The mixture is steam heated to largely denature any gluten. Then it is cut to form pieces to be fried or roasted after being spray coated with oil.